HIV care requires high medication adherence to achieve optimal clinical outcomes such as slowing the progression to AIDS. Youths face special and unique challenges to adherence. Despite a wealth of interventions designed to increase adherence outcomes, few have focused on interventions that are sustainable in resource-limited settings, or for the period of adolescence. Developing ways to increase adherence rates among adolescents is particularly important as this groups experiences the fastest growth in new HIV/AIDS cases. Existing interventions often require scarce human resources, limiting their practical use. Novel ways of adapting traditional interventions in a sustainable manner are important in resource-limited settings, where second-line therapy is often too expensive or altogether unavailable. The recent rapid rise in mobile phone coverage and ownership among developing country populations has spawned the advent of mobile-phone based interventions to improve health service delivery; short message service (SMS)-based interventions have been found to increase adherence rates to ART among adult patients. However, more knowledge about this promising technology is needed as currently no clear-cut evidence exists about the pathways through which they work. The proposed study 'SMS as an Incentive To Adhere' (SITA) proposes novel ways of using SMS messages that are explicitly grounded in the theoretical framework of Social Cognitive Theory (SCT). The first intervention is that of self-monitoring, i.e. providing participants with feedback about their adherence performance. Traditionally this involves clinic visits that take up provider and patient time and resources; SIT instead suggests providing objective, real-time information measured by electronic monitoring (Wisepill) devices sent to patients by weekly SMS. Such feedback builds self-efficacy, a key SCT concept and so may contribute to improved adherence. The second intervention is based on the SCT concept of social learning. Perceived group norms, and interventions that affect those perceptions, are a key influence on health behavior among youths, providing a substitute for direct learning. This approach is adapted to a mHealth environment by providing patients not only with their own adherence information but also that of a reference (peer) group. The first aim of the study is to hold focus groups with key stakeholders to tailor the SMS-intervention to the local needs of youths. The second aim planned is a small, six-month randomized controlled trial testing the two SITA intervention groups against a control condition of usual care to determine which method of informing and motivating drug adherence can best achieve its goals. The third aim is to synthesize lessons learned and discuss them with the clinics and other key stakeholders. The purpose of such capacity building and knowledge transfer activities part of this study is to build up mHealth knowledge at Mildmay and Uganda more generally to a point where ideas can be generated and implemented locally.